Mechanized door openers have become very prevalent in homes and many commercial establishments. These devices are designed to open the door upon receipt of a signal from a keyboard, horn, pressure of tires or footsteps on a sensor etc. Garage doors are a major market for many of these devices. Garage door openers have become ubiquitous in many communities. There are a number of problems with garage door openers, however. One of the problems with garage door openers is the issue of security. Until recently, many garage door openers had a limited number of security codes and as a result, there was a risk that someone other that the home owner could open the garage by using the same manufacturer's transmitter. In addition, the security code was typically permanently installed in the garage door opener and lost transmitters could give unauthorized persons access to the premises.
A second issue with respect to garage door openers is the issue of injury to persons and property in the closing of the doors. Government standards require that there be at least two method of determining whether there is an obstruction in the path of travel. One common approach is the use of a light beam that passes from one side of the opening to the other. If an object or person is present in the path of travel, the light beam is broken and the downward travel of the door is halted. Insofar as the second means of determining whether there is an obstruction present, there are a number of approaches on the market. On approach that has been used is to ascertain whether the speed of the closing door has changed. These methods measure the speed and compare it to a base figure obtained from previous unobstructed closings. If the closure is taking longer the opener concludes there is an obstruction and terminates closure. Other approaches are also currently available.
Garage door opener setup is another area that can create problems for the installer. Once the garage door opener is installed on the door then the door opener must be adjusted so that the door reaches the ground surface on closing thus eliminating any gaps to permit ingress of vermin, cold air, and debris. Similarly, adjustment is also necessary to make sure (1) that the garage door will reverse its direction upon contact with a person or an obstruction; and (2) that the garage door is not damaged on closing because it is hitting the ground. Also needed to be adjusted after installation is the force of closure. Too great a closing force can injure a person or damage the door upon closing.